i'm an underwater scubadiving photographer and i don't know a single brand of housings or cameras that covers water damage, unless ofcourse you can prove it's due to a manufacturing error...
i'd say 99% of all flooded housings i've seen are due to the user's fault, ie. using it in rough water, waterproof seals are not suited to absorb shocks,
dirty sealings, a hair, grain of sand or dust can compromise your seal....
worn sealings, these things don't last forever, replace em !
didn't close correctly
etc....
gopro is a pretty legit brand when it comes to warranty, but don't expect em to cover stuff beyond what's reasonable .....
the gopro water damage and ski edge damage above was pretty good i think, in most cases it's the users own fault and not the manufacturer .....